2003 JR 80 help. Again!

[gagallagher04401]

Well I warmed the bike up and then I tested the compression I am getting 90 when the bike is warm. That's with the bike just warm not super hot. I did the test as the bike cooled down and then I didn't get anything above 90 I was getting 90 consistently.

Just remembered somthing though, I did not hold the throttle wide open when I did the compression test. How much will that matter?i can do it again hot, just a pain to take everything apart again to get to the spark plug.

Also how about adjusting the oil injection cable? Maybe getting to much oil?

Also how would I know if I have bad crank seals ?

 

[gagallagher04401]

Bump! Come on people I need help!

 

[gottagetacheaperhobby]

I have a jr80 here thats a mates, it has a blown crankseal on the gearbox side, it still runs well, just smokes excessively when its started until it warms up..
Its got the biggest oversize piston available, with one size up on the pilot jet from stock, and a 90 main jet. Still has the power to pop wheelies etc no problem.

Sent from my SM-T110 using Tapatalk

 

[gagallagher04401]

My67xr could you chime in on my last few posts?

Thanks !

 

[my67xr]

Sorry mate, had a flat out weekend.
If the crank seal is bad on the clutch side it will be chuffing whiteish smoke like a train

What spark plug were you running again, stock is Ngk B7ES, gap them around .028" and .032" (Use with 5K Ohm resistor cap)

I'm still trying to find a PDF service manual for you.

I was thinking about the compression, it will be down with you not holding it wot, fuel tap not on etc and kicking it over a heap of time's.
They rely on the oil in the fuel mix to help seal the ring's.

Can you notice any oil weeping from under the head's mounting face, between the head and cylinder ?
If so it may have a leaky head gasket and will be loosing compression there?
Both Velocirator and myself had to machine the head mounting face flat on out\r DS8's to correct a slight warp

 

[2 stroke power]

hey george i had the same problem as you so i took the crank case off and under the piston and inside the muffler it was full of water (the bike would start fine cold but imposable to start when it was warm. i also put a new piston and rings in and the problem was fixed.

good luck old

 

[my67xr]

^ Did you drop it in a river ?
The DS80 and JR80 are both air cooled.

 

[gagallagher04401]

Thanks all.

The only thing I did not do was hold the throttle wide open when kicking it over.

Yes I put a brand new plug in it when I got the bike. Not 100% sure on gap.
No weeping or wetness any where on the motor. No leaks, no drips. If I had a bad right crank seal wouldn't I get leak or drip from the deal being bad?

Yeah it smokes some but it all the time. Nothing out of the ordinary I do not believe. Can crank seals be changed without major engine work, like splitting the case? (No way I can do that) Would bad crank seal alter the compression?

How is the oil cable adjusted on this model? I took the side cover of. To look at it.
You have the stationary mark on the pump body and a mark on the piece that rotates when you twist the throttle. so think of a clock. My rotating piece mark is resting at 10 o'clock when throttle is closed. Mark on the pump body is at 12 o'clock and when I turn the throttle wide open the mark moves to about 2 o'clock. Is that right?

It's got to be a problem in the engine you think? I done all I can with the carb believe.

Grrrr.......so regretting this bike.

 

[my67xr]

A crank seal seal's off the crank and bottom of the cylinder to the gearbox.
So if it was leaking then you'd be losing oil from the gearbox, and it would be burning extra oil through the top end.
Spark plug would be black and sooty if the crank seal was leaking
And yeah it is easy to replace, just need's the clutch cover to come off, then the clutch and you can get to the seal then, no splitting case's
I'm not sure on oil pump setting's, my bike was disconnected when i bought it, so i just run premix.
I still can't find that service manual, i was sure i posted it here somewhere in one of the DS80 thread's

When you pulled the carby down to clean it out, did you remove the brass emulsion tube in the middle of this pic ?

I'm wondering if the float level is a bit too low, the bottom of the float should be 19mm away from the base of the carby with the float centre tab just toughing the pin in the needle (needle and seat)

 

[gagallagher04401]

No I did not remove that tube. I did try to check the float level. I believe it correct or extremely close. ( the best I could measure anyway) I let he float hang. Barely touch the pin and measure the distance from carb base to bottom of float.

So if my gear box oil is low I prob have a bad crank seal? So just undo that screw on the side of the case and see if gear box oil comes out? I do not have a dip stick on the gear oil cap. Not sure how to tell if it is low due to a bad crank seal. It does smoke a good amount under throttle.

I noticed too when in neutral it will start to rev when giving throttle but will not wind out. It like bogs, smokes but won't rev out high. Is that normal?

So you do not think it is the top end?

I wish I could just give you the bike to fix. I so tierd not knowing what is going on with it.

Anyway I can send you a video? Would that maybe help to show you what's going on maybe. You have an e-mail address I could send a couple of videos to?

Thanks so much for the help and putting up with me through all of this.

 

[my67xr]

Yeah, take the side screw out of the clutch cover and see if any gearbox oil come's out.
You may need to lean the bike to the right to get oil to dribble out if it is low on oil.

That brass tube in the middle of the carby where the main jet screw's into is the emulsion tube.
It mixes the air and fuel for the main jet, there are small hole's across it that get gummed up and cause running problem's
If the hole's are blocked then it might not be drawing enough fuel through
The emulsion tube come's out through the top from memory




The only other thing i can think of that would cause problem's and low compression is the reed valve.
The head need's to come off, then the barrel, the reed is screwed onto the bottom of the cylinder.
If the reed petal's don't sit flat against the cylinder then it will be losing compression back through the carby
Replacemnet reed's are cheap, around $22 for Boyeson Reed's and about the same for genuine Suzuki reed's.
You might get away without needing gasket's if you are careful, there is the head gasket, base gasket and reed block gasket, oh and exhaust gasket
These petal's aren't sitting flat against the backing

These are

 

[gagallagher04401]

Well I will check that tube out.

Then I guess check the reeds and at the same time allows me check the cylinder, piston and rings.

I assume when comparing the two pics. The bad reeds are bad on the "curved" part right. Its not smooth like the 2nd pic. Trying to make sure I know what to look for. Sorry.

Think I can get away without gaskets? I would have to order them will take a week to get probably.

What about torque specs for any of the bolts or nuts I will be taking off.

 

[gagallagher04401]

Imulsion tube was fine. Plenty of gear oil n the bike.

It does not matter anyway I actually sold the bike tonight.

I did learn a lot that will hopefully help me in the future but I just did not want the headache anymore.

Thank you all for all of the help.